Severe acute respiratory syndrome (SARS) (1,2) is an infectious disease caused by a newly identified human coronavirus (SARS-CoV) (3,4). SARS-CoV has a single-stranded, positive-sense RNA genome of 30 kb, and encodes 14 potential open reading frames (ORFs).
Symptoms of SARS includes fever over 38° C. and other symptoms such as headache, an overall feeling of discomfort, body aches and mild respiratory symptoms at the outset. About 10 percent to 20 percent of patients have diarrhea After 2 to 7 days, SARS patients may develop a dry cough. Most patients develop pneumonia SARS is a highly contagious infectious disease and has a mortality rate of 15 to 20%. Currently, no effective drug exists to treat SARS-CoV infection (5).
Intensive efforts are under way to gain more insight into the mechanisms of SARS-CoV replication, in order to develop targeted antiviral therapies and vaccines. Developing effective and safe vaccines and chemotherapeutic agents against SARS-CoV, however, may take years. The recent epidemic has shown that knowledge is lacking regarding the clinical management and treatment of infected patients. Ribavirin (6-12), oseltamivir (8-10), foscarnet (8), intravenous immunoglobulin (8), and other agents have been used to treat patients. Preliminary results from in vitro testing indicate that ribavirin concentrations that inhibit other viruses sensitive to ribavirin do not inhibit replication or cell-to-cell spread of the SARS-CoV (5). However, the U.S. Centers for Disease Control and Prevention concluded that further in vitro testing of antiviral drugs on other coronavirus isolates and more information on the clinical outcome of patients treated with ribavirin or other antiviral drugs in controlled trials is needed (5).